US5859579A - Current--limiting switch - Google Patents

Current--limiting switch Download PDF

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Publication number
US5859579A
US5859579A US08/586,705 US58670596A US5859579A US 5859579 A US5859579 A US 5859579A US 58670596 A US58670596 A US 58670596A US 5859579 A US5859579 A US 5859579A
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US
United States
Prior art keywords
switch according
switch
current
unlocking
mobile contact
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US08/586,705
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English (en)
Inventor
David Walter Branston
Jorg Kieser
Werner Hartmann
Reinhard Maier
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
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Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19934325030 external-priority patent/DE4325030A1/de
Application filed by Siemens AG filed Critical Siemens AG
Assigned to SIEMENS AKTIENGELSELLSCHAFT reassignment SIEMENS AKTIENGELSELLSCHAFT ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HARTMANN, WERNER, MAIER, REINHARD, KIESER, JORG, BRANSTON, DAVID WALTER
Application granted granted Critical
Publication of US5859579A publication Critical patent/US5859579A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/12—Automatic release mechanisms with or without manual release
    • H01H71/14—Electrothermal mechanisms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H77/00—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting
    • H01H77/02—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism
    • H01H2077/025—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with pneumatic means, e.g. by arc pressure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/12—Automatic release mechanisms with or without manual release
    • H01H71/127—Automatic release mechanisms with or without manual release using piezoelectric, electrostrictive or magnetostrictive trip units
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H77/00—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting
    • H01H77/02—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism
    • H01H77/04—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrothermal opening

Definitions

  • the invention relates to a current-limiting switch having current connections and contacts, of which one contact is a fixed contact and the other a mobile contact, and having an associated drive for opening the mobile contact when a predetermined electric current intensity is exceeded.
  • thermodynamic drive With such a drive, it is possible to apply sufficient switching energies in a thermal manner.
  • the contacts are arranged in a closed housing made of insulating material and a disk-shaped resistive member is arranged between the contacts.
  • An expansion volume is preferably present between the resistive member and the mobile contact in the housing made of insulating material.
  • the resistive member can consist of a plastic containing graphite, e.g., on the basis of polyethylene, or can be formed by a multitude of carbon fibers which are made into a film or felt-like consistency.
  • the mechanical switching energy required for contact separation is thus applied electrothermally in the invention.
  • the high-current discharges occurring in case of a short circuit first heats an enclosed gas volume.
  • the resulting pressure wave acts upon a movable piston and carries out the mechanical contact opening work on it.
  • One advantageous feature of the invention is that through the use of a large-area resistive member with significantly higher electrical resistance compared to a metal, a localized melting of the electrodes is prevented on the one hand through the two-dimensional distribution of the current flow. On the other hand, a uniform heating of the gas chamber is encouraged.
  • the switch according to the invention is used in power distribution networks in the low-voltage area.
  • a disruption particularly in case of short circuits
  • parts of the network must be switched away at higher-order branches.
  • the disconnection should take place as quickly as possible, in particular, still within the first affected half cycle.
  • limiting of the short-circuit current is also often required if the disconnection cannot be recognized quickly enough or rather cannot be carried out through suitable measures.
  • the limiting of the short-circuit current also results in a limiting of the amplitudes of the voltage peaks generated in the disconnection due to the inductive load component in the network and in the load and thus reduces the risk of further damages due to insulation faults, which can be brought about by such overvoltages.
  • the requirements made of the necessary components increase, and the components must exhibit high selectivity as a result.
  • a bistable limiter can also be created through appropriate design of the switch.
  • Such a switch according to the invention is lockable in the closed state and adjustable through a suitable energy store to a response threshold which lies above the maximum current to be expected in the high-load region.
  • the volume resistance In the locked state, the volume resistance is so low that the nominal current losses are negligible.
  • the intrinsic response threshold of the limiter lies on the order of magnitude of the prospective short-circuit current.
  • the contact resistances increase and thus the energy turnover in the area of the switching contacts.
  • the intrinsic response threshold drops to a value in the nominal current region.
  • the unlocking can be triggered advantageously by an electronic early short-circuit detection device.
  • This behavior is supported advantageously in that a second energy store is used which is under tension in the locked state and is constructed so as to lead to the mechanical opening of the mobile electrode of the limiter in the unlocked state. During the closing and locking of the limiter, this second energy store is automatically placed under tension.
  • the current-limiter according to the invention is capable of not only limiting the current but also completely interrupting it, i.e., functioning as an opening switch.
  • a second locking unit is provided which locks the limiter functioning as a high-speed circuit breaker in the opened state. The limiter is thus prevented from automatically going back to the closed state following successful interruption of the current. True bistable behavior is thus achieved.
  • the switch according to the invention can be achieved with a passive circuit made of RLC elements that in case the current is cut off during the current half cycle, no harmful overvoltage peaks are generated.
  • Voltage limiting elements such as zener diodes, varistors and surge diverters can be present for this purpose.
  • FIG. 1 an electrothermal switch for low-voltage applications
  • FIGS. 2 to 4 three alternative further developments of such a switch for designing bistable limiters
  • FIG. 5 a current vs. time diagram illustrating the advantageous switching behavior.
  • a housing made of insulating material is labelled 1, which forms, for example, a rotationally symmetrical hollow cylinder about an axis I.
  • the hollow cylindrical housing made of insulating material 1 is closed by a flange 6.
  • a fixed contact 2 having a current connection 2a in the axial direction is fitted rotationally symmetrically to the axis I.
  • a mobile contact 3 whose current connection 3a also extends in the axial direction I, is fitted in a lengthwise mobile manner in the housing made of insulating material 1.
  • a disk-shaped resistive member 4 is arranged such that it abuts against the surface of the fixed contact 2 with no gap. The external contour of the resistive member 4 is fitted exactly into the housing made of insulating material 1.
  • an expansion volume 9 is present circumferentially in the wall of the housing made of insulating material 1.
  • the mobile contact 3 is pressed with its current connection 3a by a spring bellows 5 on the joint face 8 of the resistive member 4.
  • the spring element 5 defines in this manner a mechanical preloading such that when it is overcome, the mobile contact 3 is shifted in the horizontal direction.
  • the shifting can be limited by a ring 10 running circumferentially in the housing made of insulating material 1, it being possible to predetermine a suitable travel path d through appropriate dimensioning of a ring-shaped shoulder part 3b on the mobile contact 3 on the one hand and of the circumferential ring 10 on the other hand.
  • the current connection 3a has at its outer end a notch 7a which can engage with an associated latch 7b.
  • Means for locking the mobile contact in the open state are implemented in this manner.
  • the described switch can be installed in conventional power distribution networks.
  • the current flows via the current connection 2a, the fixed contact 2, the resistive member 4 to the mobile contact 3, and from there via the current connection 3a back into the network.
  • the high-current discharging first heats up areally the enclosed gas volume via the fixed contact 2 and the disk-shaped resistive member adjacent to it.
  • the resulting pressure wave shifts the mobile contact 3 to the stopping point, with a locking in the open state taking place via the notch 7a and the latch 7b.
  • the response threshold of the monostable switch shown in FIG. 1 is thus determined by the pressure force of the spring 5. This means that the spring is self-triggering but not controllable.
  • the contact pressure spring 5 is fastened in FIG. 2 to an axially movable part 6b of the housing cover 6 with the parts 6a and 6b.
  • the part 6b which acts as a spring support, is locked in the position a via a locking mechanism 11a and 11b so that the spring 5 is preloaded and creates the pressure force needed for the closed state of the mobile electrode 3 on the resistive member.
  • a spring 12 provided for accelerating the opening process is preloaded.
  • the latch 11 is unlocked by an actuator 13
  • the spring support 6b is accelerated by the springs 5 and 12 in the axial direction away from the housing 1 so that the pressure force between the mobile electrode 3 and the resistive member 4 drops to very low values within a very brief interval.
  • the contact resistance increases greatly in this process and the response threshold of the electrothermal drive falls to a value within the nominal current range of the switch.
  • the electrothermal drive triggers and the switch limits and interrupts or rather opens the current within a very short time, i.e., well below the prospective short-circuit current.
  • the mechanism 3a as well as 7a and 7b locks the mobile electrode 3 and thus prevents an undesired reclosing of the switch.
  • the actuator 13 is driven and triggered, for example, by an electronic short-circuit detection device.
  • the opening spring 12 touches the mobile electrode 3 directly and thus reinforces the opening through direct mechanical acceleration. A further acceleration of the opening process and a greater limiting of the current is achieved in this manner.
  • the same effect can be achieved if the opening spring 12 is not fastened to the electrode 3 but rather to the guide element 3b or to the contact terminal 3a which is mechanically coupled to the mobile electrode 3.
  • the energy store 5 is replaced specially in FIG. 3 by a piezoelectric actuator 14 which is driven simultaneously with the unlocking actuator 13. When driven, the actuator 14 reduces its length so that the contact pressure force is already reduced before the mobile electrode 3 is moved by the opening energy store.
  • the piezoelectric actuator 14 is arranged parallel to the opening spring 12 and lengthens when driven.
  • the contact pressure force of the pressure spring 5 is briefly overcompensated as a result and the spring effect is reinforced in the initial phase of the opening procedure.
  • the diagram according to FIG. 5 illustrates the opening behavior of the new switch.
  • the curve 51 characterizes the behavior vs. time of the prospective short-circuit current.
  • the curve 52 characterizes the current through the uncontrolled limiting element of conventional construction, with the value A giving the fixed response threshold value setting.
  • the curve 53 characterizes the current through the new bistable limiter or rather high-speed circuit breaker, with the response threshold B of the locked limiter lying at or even above the prospective maximum short-circuit current.
  • the response threshold C of the unlocked limiter lies within the nominal current range I nenn so that triggering can occur very early for non-dangerous current values. The triggering takes place through active unlocking via the early short circuit recognition electronics and the unlocking actuator 13.
  • the early short circuit recognition electronics detects short circuits within only a few microseconds after current zero. Due to the low moving masses in the actuator 13 and in the locking mechanism 11a and 11b, very early current limiting and opening is achieved in the switch so that the currents which actually occur can be limited to non-hazardous values within the nominal current range.
  • the selectivity is achieved through the threshold value setting of the early short-circuit detection device and is thus adjustable within broad limits for an individual electromechanical switching element of type "BISTABLE LIMITER".
  • the actuator 13 used for unlocking can be designed as an electromechanical or electromagnetic actuator. However, it can also be designed as a piezoelectric or piezostrictive element in order to accelerate the unlocking process due to decreased accelerated masses. Moreover, an actuator having a magnetostrictive element as an active component can be used.
  • bistable limiter which functions as a current limiter can be combined with an electronic early short-circuit detection device. Likewise in this combination, the limiter can work as a current-limiting high-speed circuit breaker. Suitable circuits for early short-circuit recognition are known from the prior art.
  • the resistive member 4 can consist of a conductive plastic such as the known polyethylene which is made electrically conductive. Graphite is used as a filler, for example.
  • the resistive member 4 can also be made of graphite fibers which are made into a film- or felt-like consistency through suitable processing.
  • a non-organic material with defined conductivity can also be used instead of the previously used organic material which was made conductive, such as polyethylene filled with carbon black.
  • a resistive member highly doped semiconductor materials such as, in particular, polycrystalline silicon carbide can also be used.
  • the spatial form can deviate from the rotational symmetry and can be present rectangularly with areal resistive members, for example. Multiple resistive members can also be connected in series. Moreover, suitable means for ventilating the inside of the housing made of insulating material 1 can also be provided.

Landscapes

  • Switches Operated By Changes In Physical Conditions (AREA)
  • Thermally Actuated Switches (AREA)
  • Arc-Extinguishing Devices That Are Switches (AREA)
US08/586,705 1993-07-26 1994-07-25 Current--limiting switch Expired - Lifetime US5859579A (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE19934325030 DE4325030A1 (de) 1993-07-26 1993-07-26 Schalter zur Strombegrenzung
DE4425330.3 1994-07-18
DE4425330A DE4425330A1 (de) 1993-07-26 1994-07-18 Schalter zur Strombegrenzung
DE4325030.0 1994-07-18
PCT/DE1994/000862 WO1995003619A1 (de) 1993-07-26 1994-07-25 Schalter zur strombegrenzung

Publications (1)

Publication Number Publication Date
US5859579A true US5859579A (en) 1999-01-12

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ID=25928039

Family Applications (1)

Application Number Title Priority Date Filing Date
US08/586,705 Expired - Lifetime US5859579A (en) 1993-07-26 1994-07-25 Current--limiting switch

Country Status (5)

Country Link
US (1) US5859579A (de)
EP (1) EP0750788B1 (de)
JP (1) JP3636461B2 (de)
DE (2) DE4425330A1 (de)
WO (1) WO1995003619A1 (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080179170A1 (en) * 2005-04-22 2008-07-31 Norbert Beyrard Circuit Breaker-Contactor With A Piezo-Electric Controlled Locking
US20090046403A1 (en) * 2004-07-27 2009-02-19 Michael Anheuser Breaker device for low-voltage applications
US20150064959A1 (en) * 2013-09-03 2015-03-05 Chuan-Sheng Wang Socket having overheating destructive limiting element
US9225395B2 (en) 2000-12-01 2015-12-29 Intel Corporation Antenna control system and method
US20160379790A1 (en) * 2013-12-17 2016-12-29 Siemens Aktiengesellschaft A protective electronic module for an hvdc convertor
US9627821B1 (en) * 2016-07-27 2017-04-18 Atom Technology Inc. Power connector having a transparent observation portion to view the status of a contact limiting member
US20210375945A1 (en) * 2017-03-28 2021-12-02 Kenneth G. Blemel Method, System, and Apparatus to Prevent Electrical or Thermal-Based Hazards in Conduits

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4446045A1 (de) * 1994-12-22 1996-06-27 Siemens Ag Schalter zur Strombegrenzung
DE19912713A1 (de) * 1999-03-20 2000-09-21 Abb Research Ltd Stromleitersperreinrichtung
KR100697917B1 (ko) * 2005-01-12 2007-03-20 엘에스전선 주식회사 Ｐｔｃ 한류기
DE102011108949A1 (de) * 2011-07-29 2013-01-31 Ceramtec Gmbh Elektromagnetisches Relais
CN109959050A (zh) * 2017-12-22 2019-07-02 北京绿能嘉业新能源有限公司 一种过热保护电暖坑板
CN108962702A (zh) * 2018-08-14 2018-12-07 李涵 一种调压式熔断器

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3356808A (en) * 1966-02-28 1967-12-05 Westinghouse Electric Corp Circuit-interrupting devices having pressure-operated contacts
US3743993A (en) * 1972-02-02 1973-07-03 Gen Electric Thermal overload protective device
US3848213A (en) * 1973-10-15 1974-11-12 Therm O Disc Inc Time delay relay
US3987388A (en) * 1974-08-29 1976-10-19 Bbc Brown Boveri & Company Limited Current limiting device
GB2042265A (en) * 1979-02-15 1980-09-17 Standard Telephones Cables Ltd Electrical overload cut-out device
US4419650A (en) * 1979-08-23 1983-12-06 Georgina Chrystall Hirtle Liquid contact relay incorporating gas-containing finely reticular solid motor element for moving conductive liquid
EP0102574A2 (de) * 1982-08-21 1984-03-14 Limitor AG Bimetallschutzschalter
US4481498A (en) * 1982-02-17 1984-11-06 Raychem Corporation PTC Circuit protection device
US4510480A (en) * 1981-06-09 1985-04-09 Ranco Incorporated Thermostat with temperature pull-down facility
US4542365A (en) * 1982-02-17 1985-09-17 Raychem Corporation PTC Circuit protection device
US4549161A (en) * 1982-02-17 1985-10-22 Raychem Corporation PTC Circuit protection device
US4550301A (en) * 1982-02-17 1985-10-29 Raychem Corporation PTC Circuit protection device
US4642136A (en) * 1984-06-11 1987-02-10 Kabushiki Kaisha Toshiba PTC ceramic composition
WO1991012643A1 (en) * 1990-02-08 1991-08-22 Asea Brown Boveri Ab Device for motor and short-circuit protection
EP0487920A1 (de) * 1990-10-30 1992-06-03 Asea Brown Boveri Ab Komponente mit positiven Temperaturkoeffizienten

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3356808A (en) * 1966-02-28 1967-12-05 Westinghouse Electric Corp Circuit-interrupting devices having pressure-operated contacts
US3743993A (en) * 1972-02-02 1973-07-03 Gen Electric Thermal overload protective device
US3848213A (en) * 1973-10-15 1974-11-12 Therm O Disc Inc Time delay relay
US3987388A (en) * 1974-08-29 1976-10-19 Bbc Brown Boveri & Company Limited Current limiting device
GB2042265A (en) * 1979-02-15 1980-09-17 Standard Telephones Cables Ltd Electrical overload cut-out device
US4419650A (en) * 1979-08-23 1983-12-06 Georgina Chrystall Hirtle Liquid contact relay incorporating gas-containing finely reticular solid motor element for moving conductive liquid
US4510480A (en) * 1981-06-09 1985-04-09 Ranco Incorporated Thermostat with temperature pull-down facility
US4542365A (en) * 1982-02-17 1985-09-17 Raychem Corporation PTC Circuit protection device
US4481498A (en) * 1982-02-17 1984-11-06 Raychem Corporation PTC Circuit protection device
US4549161A (en) * 1982-02-17 1985-10-22 Raychem Corporation PTC Circuit protection device
US4550301A (en) * 1982-02-17 1985-10-29 Raychem Corporation PTC Circuit protection device
EP0102574A2 (de) * 1982-08-21 1984-03-14 Limitor AG Bimetallschutzschalter
US4642136A (en) * 1984-06-11 1987-02-10 Kabushiki Kaisha Toshiba PTC ceramic composition
WO1991012643A1 (en) * 1990-02-08 1991-08-22 Asea Brown Boveri Ab Device for motor and short-circuit protection
EP0487920A1 (de) * 1990-10-30 1992-06-03 Asea Brown Boveri Ab Komponente mit positiven Temperaturkoeffizienten

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9225395B2 (en) 2000-12-01 2015-12-29 Intel Corporation Antenna control system and method
US20090046403A1 (en) * 2004-07-27 2009-02-19 Michael Anheuser Breaker device for low-voltage applications
US7916442B2 (en) 2004-07-27 2011-03-29 Siemens Aktiengesellschaft Breaker device for low-voltage applications
US20080179170A1 (en) * 2005-04-22 2008-07-31 Norbert Beyrard Circuit Breaker-Contactor With A Piezo-Electric Controlled Locking
US7528334B2 (en) * 2005-04-22 2009-05-05 Norbert Beyrard Circuit breaker-contactor with a piezo-electric controlled locking
US20150064959A1 (en) * 2013-09-03 2015-03-05 Chuan-Sheng Wang Socket having overheating destructive limiting element
US9257798B2 (en) * 2013-09-03 2016-02-09 Chuan-Sheng Wang Socket having overheating destructive limiting element
US20160379790A1 (en) * 2013-12-17 2016-12-29 Siemens Aktiengesellschaft A protective electronic module for an hvdc convertor
US10109444B2 (en) * 2013-12-17 2018-10-23 Siemens Aktiengesellschaft Electronic module for protecting a HVDC converter from current surges of energy discharges from a capacitor of the converter
US9627821B1 (en) * 2016-07-27 2017-04-18 Atom Technology Inc. Power connector having a transparent observation portion to view the status of a contact limiting member
US20210375945A1 (en) * 2017-03-28 2021-12-02 Kenneth G. Blemel Method, System, and Apparatus to Prevent Electrical or Thermal-Based Hazards in Conduits

Also Published As

Publication number Publication date
EP0750788A1 (de) 1997-01-02
JP3636461B2 (ja) 2005-04-06
EP0750788B1 (de) 1998-03-25
DE59405547D1 (de) 1998-04-30
JPH09501003A (ja) 1997-01-28
WO1995003619A1 (de) 1995-02-02
DE4425330A1 (de) 1996-01-25

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